The ball moves along an inclined groove, turning into a circle with a radius of 0.4 m.

The ball moves along an inclined groove, turning into a circle with a radius of 0.4 m. From what minimum height should the ball begin to move so that it does not break away from the groove at the top point of the circle?

Decision:
mg (h + 2r) = mv ^ 2/2 + mg2r
mgh + mg2r = mv ^ 2/2 + mg2r
mgh = mv ^ 2/2
h => / 2g / v ^ 2
since the ball should not come off => N = 0 and mg = ma
a = g a = v ^ 2 / r v ^ 2 = ar
h = √2 * g / gr = 2.234 m
Answer: 2.234 m